Macrophages play a critical role in resolution of inflammation and/or tissue injury repair (see, e.g., Mantovani et al., Eur J Cancer 40(11):1660-1667 (2004); Duffield et al., J Clin Invest 115(1):56-65 (2005); Nahrendorf M, et al., J Exp Med 204(12):3037-3047 (2007); Arnold et al., J Exp Med 204(5):1057-1069 (2007); Fallowfield et al., J Immunol 178(8):5288-5295 (2007); and Castano et al., Science Trans1 Med 1(5):5ra13 (2009)) and macrophage Wnt ligands establish tissue homeostasis during development (Lobov I B, et al., Nature 437(7057):417-421 (2005)).